Add 26 golden Oreos to a food processor and pulse until you have fine, even crumbs.

Transfer crumbs to a bowl, add the melted butter, and stir until all crumbs are evenly coated.

Press the mixture evenly into a 9-inch tart dish, pushing it slightly up the sides. Bake at 325°F for 10–12 minutes until slightly golden. Let cool completely before filling.

In a medium heatproof bowl, whisk together the eggs, egg yolks, sugar, lemon zest, lemon juice, and heavy cream until smooth and combined.

Set the bowl over a saucepan of gently simmering water (bain-marie), ensuring the bowl bottom does not touch the water. Cook over moderate heat, whisking constantly, for 10–20 minutes until the curd thickens and reaches 170°F, or coats the back of a spoon with a clear finger trail.

Remove from heat immediately and strain through a fine mesh sieve into a clean bowl.

Add the cold butter cubes a few pieces at a time, whisking until each addition is completely melted and incorporated before adding more. The curd will become beautifully silky and glossy.

Allow the curd to cool to room temperature, whisking occasionally. It will continue to thicken as it cools.

Pour the cooled curd into the completely cooled Oreo crust. Spread evenly. Refrigerate for at least 4 hours, or overnight, until completely set.

Slice with a sharp, warm knife. Serve with fresh berries, whipped cream, and a dusting of powdered sugar if desired.